This invention relates to reaction engines and more particularly to ducted rockets which consist chiefly of a primary chamber containing the fuel-rich propellant and a secondary chamber for after-burning of the reaction products from the primary chamber, which products are mixed with inducted air.
Most particularly, the present invention deals with mixing and combustion of a fuel-rich, particle laden jet in a secondary airstream in an air breathing ducted rocket, for example. In rockets of this type which are special types of ramjets, fuel-rich solid propellants having high mass fractions of metals (e.g., boron) are burned in a primary chamber to produce combustion products containing unreacted gaseous and particulate fuels. The exhaust flow of the primary chamber must be supersonic. This is satisfied by any configuration of the primary nozzle that produces a supersonic flow. Said supersonic flow insures that the primary chamber pressure is at least twice the secondary chamber pressure, which prevents secondary chamber pressure fluctuations from effecting the primary chamber pressure. The primary chamber products are injected into a secondary chamber where they mix, ignite, and burn with a subsonic airstream. For maximum overall efficiency these processes must be completed before the gas/particle mixture is ejected from the rocket nozzle.
A further and more complete background of the invention may be had by reference to the following.
1. Schadow, K., "The Influence of Combustion Parameters on the Combustion of Particle-Laden Fuels in Ducted Flow," Eleventh Aerospace Sciences Meeting, Washington, D.C., AIAA Paper 73-177, January 1973.
2. Schadow, K., "Boron Combustion Characteristics in Ducted Rockets," COMBUST SCI AND TECH, Vol. 5, No. 4, June 1972, p. 107.
3. Schadow, K., "Study of Gaseous Nonequilibrium Effects in Particle-Laden Ducted Flows for Improvement of the Combustion Efficiency," AIAA Paper 72-36, Tenth Aerospace Sciences Meeting, San Diego, CA., January 1972.
4. Schadow, K., "Study of Gas-Phase Reactions in Particle-Laden, Ducted Flows," AIAA J, Vol. 11, No. 7, July 1973, p. 1042.
5. Abbott, S. W., Smoot, L. D., and Schadow, K., "Direct Mixing and Combustion Efficiency Measurements in Ducted, Particle-Laden Jets," AIAA J, Vol. 12, No. 3, March 1974, pp. 275-82.
6. Roberts, R., "Boron Combustion: A review," Ninth International Symposium on Space Technology and Science, Tokyo, 1971.
7. Barrere, M., "Rocket Propulsion," Elsevier Pub. Co. 1960, pp. 389-99.